The term 'move surreptitiously' can be defined as moving in a secretive or stealthy manner. The crossword solutions for this term are 'SNEAK' and 'CREEP', both of which are five-letter words. To SNEAK is to move quietly and cautiously, often in order to avoid being seen or heard. To CREEP is to move slowly and carefully, usually in an effort to remain undetected. Both terms imply a sense of secrecy and caution when moving.